In working vehicles, rotational power from an engine is changed in speed at a transmission and is then transmitted to a pair of front wheels or a pair of rear wheels, which function as driving wheels. Among them, working vehicles each including a cabin that surrounds a driver's seat have been conventionally used as a tractor and the like.
However, such a conventional working vehicle provided with a cabin has possibility for improvement in view of stably supporting the heavy cabin in a vibration-isolation manner.
For example, in a conventional working vehicle provided with a cabin, a pair of front plates, a pair of cabin brackets, and four brackets for a transmission case at front, rear, right, and left positions are fixedly attached to front portions, intermediate portions, and rear portions of a pair of right and left main frames, respectively. The cabin is supported by the front plates and the cabin brackets in a vibration-isolation manner, and the transmission case is supported by the brackets for the transmission case (see Patent Document 1 which is mentioned below).
More specifically, in the conventional working vehicle provided with a cabin, the pair of main frames are coupled to each other at the front portions and the intermediate portions by a front link frame and a coupling frame for a working device coupler, respectively.
The front plates each have an outer end coupled to the corresponding main frame and a rear end coupled to the front link frame. The cabin brackets each have an outer end coupled to the corresponding main frame at a position immediately behind the coupling frame
As described above, in the conventional working vehicle provided with a cabin, the rear ends of the front plates are coupled to the front link frame, and the cabin brackets are disposed immediately behind the coupling frame, so as to increase the rigidity at the support points at which the cabin is supported. However, all of the four cabin support points at the front, rear, right, and left positions are located on the pair of main frames. Accordingly, it is not possible to realize an enough stable support for the cabin.